1. Field of the Invention
The present invention relates to a novel reamer means for use in remodeling a femoral superior neck to provide an excavation in the cortico-cancellous bony envelope thereof for facilitating acceptance therein of a prosthetic means in the form of an intramedullary insert, especially an intramedullary insert having an upper offset or flange, and a method for such remodeling or excavating.
2. Prior Art
The prior art in this field is well set forth in my prior U.S. Pat. No. 5,133,766 which, among other things, discloses a novel femoral insert and a drilling fixture or jig for use in connection with the remodeling of a femoral head to facilitate insertion thereinto of an intramedullary insert which normally, in its finished form, includes an attached or integral shell or cap, so that the remodeled femoral head including the intramedullary insert may be employed with an intact acetabulum, namely, the cup-shaped socket in the hip bone, or in combination with a prosthetic acetabular socket or cup of a type widely available from orthopedic supply organizations today.
In my prior patent, the drilling fixture or jig was particularly adapted to produce a cavity in the femoral head which corresponded to the particular shape or configuration of the offset portion of the intramedullary insert disclosed in my said earlier patent, which was provided with a wedge-shaped offset comprising a plurality of adjoining convexly-arcuate surface segments. In the present case, the reamer device or means of the present invention is particularly adapted for the creation of a suitable excavation or cavity in the femoral superior neck for the reception therein of an intramedullary insert, and especially an upper flange or offset portion of an intramedullary insert, which offset portion may take various shapes, forms, and sizes, but especially an intramedullary insert which has an offset portion having not necessarily parallel but essentially planar sides, which offset is readily insertable into the cavity thus produced, and which optimally conforms precisely to the shape, form, and size, including the width and length and depth of the cavity, but which may if desired by the surgeon be additionally secured therein by the employment of the usual surgical hammer, cement, or the like. When the offset portion of the intramedullary insert does not have planar sides corresponding to the cavity or excavation produced using the reamer means of the present invention, but which optionally may have concave or convex side surfaces, or side surfaces comprising apertures or indentations, the cavity produced by employment of the reamer means of the present invention is equally suitable for the reception of such offset portion of an intramedullary insert. In such case it generally becomes more essential that the offset portion of the intramedullary insert be further secured in the cavity by the employment of the usual medical hammer, cement or the like, although it is possible even in such cases that the close fit between the offset portion of the intramedullary insert and the cavity produced using the reamer means and method of the present invention is sufficiently corresponding and close or tight so that no excessively forceful hammering or medical cement may be required, all of course as determined by the orthopedic surgeon in charge.
Although the intramedullary insert of my prior patent and the drilling fixture or jig disclosed therein are highly advantageous, not all intramedullary inserts have or will have the type of offset portion disclosed and claimed in my prior patent, and many will comprise an offset portion having essentially planar side surfaces, with or without apertures, porous coatings, grooves, pits, or indentations, so that an improved reamer means which is particularly adapted for the creation of a cavity in the femoral superior neck which will be adaptable to and even especially suitable for the reception therein of such type of intramedullary insert, as well as intramedullary inserts which do not comprise an offset portion having essentially planar side surfaces, has now become a requirement, want, or need of the art, and the present invention is designed to fulfill such need for a reamer device or means, which is generally applicable and widely adaptable to numerous types of intramedullary inserts with numerous types of offset portions including even an insert according to my prior invention and patent, as well as a method for producing a cavity in the femoral head therewith, in a convenient and reliable manner.